/// <summary>
/// Processes the supplied ApplyWhen element.
/// </summary>
public override ProcessNodeResults ProcessNode(
[NotNull] XElement element,
[NotNull] IConfiguration configuration)
{
if (element == null)
{
throw new ArgumentNullException(nameof(element));
}
if (configuration == null)
{
throw new ArgumentNullException(nameof(configuration));
}
if (element.Name.LocalName != "Apply" ||
element.Name.Namespace != XmlTemplate.ConfigGenXmlNamespace)
{
throw new ArgumentException("Supplied element should have name 'Apply' in the configgen namespace.", nameof(element));
}
IResult <ApplyElement, string> result = _applyElementCreator.Create(element);
if (!result.Success)
{
element.Remove();
return(ProcessNodeResults.CreateErrorResult(XmlTemplateErrorCodes.ApplyWhenElseFormatError, result.Error));
}
bool trueConditionAlreadyEvaluated = false;
ApplyElement applyElement = result.Value;
while (applyElement.PredicateSubNodes.Count > 0)
{
var subNode = applyElement.PredicateSubNodes.Dequeue();
// if we've already evalutated a true, don't bother evaluating sub node conditions, just return a fail result
ExpressionEvaluationResults evaluationResults = trueConditionAlreadyEvaluated
? new ExpressionEvaluationResults(false, null, null, null)
: EvaluateCondition(subNode.Element, configuration, _configurationExpressionEvaluator);
if (evaluationResults.ErrorCode != null)
{
element.Remove();
return(ProcessNodeResults.CreateErrorResult(evaluationResults.ErrorCode, evaluationResults.ErrorMessage));
}
ProcessElement(subNode, evaluationResults.Result && !trueConditionAlreadyEvaluated);
trueConditionAlreadyEvaluated |= evaluationResults.Result;
}
if (applyElement.FinalElseSubNode != null)
{
ProcessElement(applyElement.FinalElseSubNode, !trueConditionAlreadyEvaluated);
}
element.Remove();
return(ProcessNodeResults.CreateSuccessResult());
}
public virtual IResult <ApplyElement, string> Create(XElement applyElement)
{
if (applyElement == null)
{
throw new ArgumentNullException();
}
var returnValue = new ApplyElement();
var xname = XName.Get("When", XmlTemplate.ConfigGenXmlNamespace);
var predicateElements = applyElement.Elements();
var primaryPredicate = predicateElements.FirstOrDefault();
if (primaryPredicate == null ||
primaryPredicate.Name != xname)
{
return(Result <ApplyElement, string> .CreateFailureResult("The first element in the 'Apply' container must be a 'When' element in the ConfigGen namespace."));
}
var onNotAppliedAttribute = applyElement.GetOnNotAppliedAttribute(OnNotAppliedAction.Remove);
var result = _applyElementSubNodeCreator.Create(primaryPredicate, onNotAppliedAttribute);
if (!result.Success)
{
return(Result <ApplyElement, string> .CreateFailureResult(result.Error));
}
returnValue.PredicateSubNodes.Enqueue(result.Value);
foreach (var currentElement in primaryPredicate.ElementsAfterSelf())
{
if (currentElement != null)
{
if (returnValue.FinalElseSubNode != null)
{
return(Result <ApplyElement, string> .CreateFailureResult("The 'else' element must be the final element in the 'Apply' container."));
}
if (currentElement.Name == XName.Get("ElseWhen", XmlTemplate.ConfigGenXmlNamespace))
{
result = _applyElementSubNodeCreator.Create(currentElement, onNotAppliedAttribute);
if (!result.Success)
{
return(Result <ApplyElement, string> .CreateFailureResult(result.Error));
}
returnValue.PredicateSubNodes.Enqueue(result.Value);
}
else if (currentElement.Name == XName.Get("Else", XmlTemplate.ConfigGenXmlNamespace))
{
result = _applyElementSubNodeCreator.Create(currentElement, onNotAppliedAttribute);
if (!result.Success)
{
return(Result <ApplyElement, string> .CreateFailureResult(result.Error));
}
returnValue.FinalElseSubNode = result.Value;
}
else
{
return(Result <ApplyElement, string> .CreateFailureResult("Unexpected node appeared in 'Apply' container: " + currentElement.Name));
}
}
}
return(Result <ApplyElement, string> .CreateSuccessResult(returnValue));
}
